The present inventive concept relates to a semiconductor device having multiwork function gate patterns and a method of fabricating the same.
In view of the requirements of high integration and high operation speed, gate insulating layers and gate electrodes of CMOS semiconductor devices are required to be ultra-thin. In order to overcome limitations on the physical dimensions of ultra-thin gate insulating layers and manufacturing processes thereof, high-k gate insulating layers have been used. In order to control the work function of semiconductor devices having high-k gate insulating layers and metal gate structures, the thickness of barrier layers of the metal gate structures have been controlled. However, typical methods of controlling the thickness of barrier layers have become virtually impossible to carry out due to the reduced size of semiconductor devices.